The Effect Of Inflammation-related KP On The Expression Of Apoptotic Proteins Bcl-2 And Caspase3 In Hippocampus After Circadian Rhythm Disorder In Mice

Objective: to observe the pathological changes of colon tissues in mice after continuous light exposure,and the levels of TNF-α and IL-1β proinflammatory factors in the colon and hippocampus.The level of IDO,the key enzyme of KP metabolic pathway,and the changes of related metabolites(KYN,3-HK)in colon,blood and hippocampus;Expression of apoptotic proteins Bcl-2 and Caspase-3 in hippocampus of mice after continuous light exposure;To further explore the possible pathways of inflammatory signals and KP metabolites between the brain and the intestine,as well as the effects of inflammation-related KP pathway on the expression of apoptotic proteins Bcl-2 and Caspase3 in the hippocampus of mice after continuous light exposure.Methods: the model of circadian disorder was established by continuous illumination.C57BL/6J 6-week old male mice were selected to be caged under normal circadian rhythm for 1 week,and then randomly divided into normal rhythm group(LD group)and continuous light group(LL group),with 12 mice in each group.After4 weeks of modeling,the mice in each group were sacrificed with their eyeballs plucked.1.The pathological changes of colon tissues in mice were observed by HE staining;2.The levels of TNF-α,IL-1β,KYN,3-HK and IDO in colon tissues were detected by Elisa.3.Blood levels of KYN and 3-HK were detected by Elisa.4.TNF-α,IL-1β,KYN,3-HK levels in hippocampal tissue were detected by Elisa.5.The expression levels of apoptotic proteins Bcl-2 and Caspase-3 in hippocampus were detected by Western Blot.Results:1.HE staining showed that the pathological changes in the colon tissues of mice after 4 weeks of continuous light showed diffuse infiltration of lymphocytes in the laminaria propria of the mucosa,with no significant reduction in the number of goblet cells and colonic glands,but irregular arrangement,compared with those in the LD group.2.ELISA results showed that after 4 weeks of continuous light exposure,the levels of the inflammatory factor TNF-α and IL-1β in the hippocampal and colic tissues of the mice were higher than those in the LD group,with statistical differences(hippocampal: P < 0.005,colon: P < 0.05).The level of IDO in colon tissues was higher than that in LD group,but >0.05,no statistical difference;However,the levels of KYN and 3-HK,metabolites related to KP metabolic pathway in colon tissues,were significantly higher than those in LD group(P < 0.005,respectively).P <0.05);The blood level of KYN was higher than that of LD group(P < 0.001),and the level of 3-HK was higher than that of LD group,but P>0.05,no statistical difference;The content of KYN in the hippocampal tissues of mice was higher in LL group than in LD group(P < 0.05),while the content of 3-hk in LL group was higher than that in LD group,but P >0.05,no statistical difference.3.Western Blot results showed that the protein expression level of apoptotic egg caspase-3 in the hippocampal tissue of mice after 4 weeks of continuous light exposure was higher than that of the LD group without significant difference(P>0.05),the protein expression level of apoptotic inhibitor Bcl-2 was higher than that of the LD group with no significant difference(P>0.05).Conclusion:1.After continuous light exposure,the levels of lymphocyte infiltration and the inflammatory factor TNF-α in the colon tissues of the mice increased,resulting in inflammatory changes.The increased levels of KYN and 3-HK in the colon tissues may be related to the activation of KP pathway under the action of inflammation.2.After continuous exposure to light,increased levels of the inflammatory cytokines TNF-α and IL-1β,and their levels in the hippocampal tissue produced inflammatory changes.The increased levels of KYN in the hippocampal tissue may be related to the activation of KP pathway under the action of inflammation.3.There was no significant difference in the expression of pro-apoptotic protein caspase-3 and anti-apoptotic protein Bcl-2 in the hippocampal tissue of mice after continuous light exposure.4.The inflammation-related KP pathway after continuous illumination had little correlation with the expression of apoptotic proteins Bcl-2 and caspase-3 in the hippocampus of mice.